1. Field of the Invention
The present invention relates generally to a Radio Resource Management (RRM) technique in a cellular communication system and more particularly to RRM in cellular communication system including Relay Stations (RSs) using dedicated lines, and a Mobile Station (MS) located at a coverage boundary of an RS receives the same resources from two neighboring RSs through collaborative scheduling to increase Quality of Service (QoS) of its channel by signal combining.
2. Description of the Related Art
Efficient management and allocation of frequency resources is one of the major core technologies for continuous development of communication systems. To this end, multi-hop transmission schemes have been widely used, which are extended from the conventional single-hop transmission scheme that allow only the direct transmission from one Base Station (BS) per cell to the MSs within the cell. In a system supporting multi-hop transmission, a signal from a BS is transmitted to an MS via an RS, and direct transmission from the BS to the MS is also possible. A structure of a single-hop system has one BS per cell without a relay, and in this structure, a terminal, or MS, is directly connected to the BS without separate relay. A relay system additionally installs relays between the BS and MSs to improve signal reception performance of MSs located at a cell boundary or a shadow area. Of the multi-hop transmission schemes, a wireless multi-hop transmission scheme has been widely used, which connects the link between the BS and the RS in a wireless manner.
The RS system can be classified into a wired optical fiber RS system and a wireless Radio Frequency (RF) RS system according to the link between the BS and the RS. The wired RS has less signal attenuation but has no mobility, while the wireless RS has low installation cost, but amplifies and broadcasts all received signals regardless of the signal desired by an MS and an interference signal. Recently, in order to save resources necessary for BS-RS data transmission of the wireless multi-hop system, intensive research is being conducted to secure more resources that can be transmitted to MSs by replacing the BS-RS link with the wired optical fiber, and to efficiently apply the centralized RRM technique through the BS-RS wired link.